Thompson: you asked where the £10,000 went. I can't answer that personally because I haven't got involved in permanent residency applications. But I can tell you something about why the temporary has gone up so much. Part of it is a NHS surcharge: forgive a lengthy cut and paste.
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1. When is the health surcharge being introduced? The surcharge will be introduced on 6 April 2015. It will apply to applications where payment is made on or after 6 April.
2. How much will it cost? The health surcharge will be set at £200 a year for temporary migrants and £150 a year for students. Dependants will generally be charged the same amount as their main applicant. The total surcharge amount for the whole period of leave granted will be payable upfront.
3. Why is the surcharge being introduced?
The immigration health surcharge will ensure that temporary, non-EEA migrants coming to the UK for more than six months contribute to the NHS in a manner in line with their immigration status.
The surcharge is not a visa fee. The payment will be collected by the Home Office and it will go directly into the National Health Service (NHS) and will give migrants access to the NHS on the same terms as a permanent UK resident.
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So for two and a half years, that's £500 per person. You may notice several possible criticisms in this. The first is that it is not related in any way to the NI or tax contributions the person has made in the past. So the fact a person may have made exactly the same contributions as a UK resident of the same age is of no relevance: they must pay exactly the same as someone just turning up in the UK as a 'health tourist' who has never set foot in the country before. Secondly, if it is about preventing health tourism the fee is probably far too low to have any influence. If you are facing paying tens of thousands for an operation at home, or a £200 per year charge (and you don't intend to stay more than a year), it is pretty clear which you will pick. So as a means of preventing health tourism it is very likely ineffective.

There is another part of the costs that has gone up a few hundred pounds that is in principle an optional charge but in practice for many people they have no choice. You can pay extra to have the application fast tracked so it completes in a week or so rather than three months. However, you have to send passports, marriage certificates and so forth as part of the application and these are only returned at the end of the process. Which can mean trying to live in the UK for three months without any of the official forms of ID.